Amid a federal investigation into complaints that its handling of sexual assault cases violated civil rights law, Harvard University announced a new policy Wednesday and a centralized way to investigate such complaints.

The new sexual and gender-based harassment policy, to take effect at the start of the 2014-15 school year, comes just over a year after the campus in Cambridge, Mass., set up a working group to review policies and hired its first university-wide Title IX officer to oversee compliance with the federal law that bans gender discrimination in education.

The policy shift is another indication that institutions are responding to the growing chorus of concerns about a “rape culture” on college campuses.

“It’s a really important move … and it’s making it very clear that the activism Harvard students have participated in … around Harvard’s antiquated policies is actually making change,” says Tracey Vitchers, a spokeswoman for SAFER (Students Active For Ending Rape) in New York.

A central body of trained investigators will look into complaints by students and report to the Harvard Title IX coordinator. It will report findings and recommend measures to the disciplinary body of the school involved. (Harvard encompasses 13 schools, all of which have to bring their policies into line with the central policy.)

Investigators will use a “preponderance of the evidence” standard in determining whether sexual assault or other policy violations occurred. This standard, meaning there’s more than a 50 percent likelihood that the accusation is true, is in line with guidance issued to schools by the US Department of Education’s Office for Civil Rights (OCR). It is opposed by advocates for individual rights of the accused.

The new policy allows complainants to request anonymity, but cautions that it may lead to a hampered investigation or alternative resolution, The Harvard Crimson reports.

The policy does not include one element that some student activists have pushed for: an “affirmative consent” requirement, which would have opened the door for complaints if someone did not explicitly communicate consent to participate in sexual activity.

“Affirmative consent” has become a hotly contested issue in recent years, Ms. Vitchers says, and schools often try to balance their own explanations of consent with local and state laws. “Many schools are trying to clarify what it means to obtain consent” and under which circumstances a person is not fit to give consent (intoxication, for instance), she says.

Antioch College in Ohio is considered the most stringent in requiring that students agree verbally to every stage of a sexual encounter. A bill proposed in California recently would require students at state colleges and universities to consciously and unambiguously agree to engage in sexual activity.

The standard in Harvard’s policy is to prohibit “unwelcome conduct of a sexual nature,” Title IX officer Mia Karvonides said in a Q&A published by Harvard’s public affairs office. While the policy is more detailed, Ms. Karvonides said, “essentially conduct is unwelcome if a person did not request or invite it and regarded the conduct as undesirable or offensive.” And “unwelcome conduct” extends beyond what would be considered a criminal offense, she said.

Harvard officials submitted the new policy to OCR for review in April, but decided to move forward with implementation for the coming school year while awaiting feedback.

Harvard College and Havard University Law School are two of the 55 institutions under investigation by OCR for Title IX sexual assault or harassment complaints, according to a list that was publicized in the spring.

Dartmouth College, in Hanover, N.H., is also on the list, and announced broad revisions to its sexual assault policies last month, including an independent investigator to examine complaints.

Some critics say OCR is going too far in pressuring schools into settlements that heavily favor complainants. Hans Bader, a former Education Department lawyer, for instance, has written commentaries criticizing a recent settlement with Tufts University in Medford, Mass., for requiring the school to take “interim measures” against students accused of sexual assault before any finding of guilt, including things like removing the accused from a dorm or classroom setting.

Advocates for stronger sexual assault policies on campus say such steps are sometimes necessary because of the trauma that can be caused by having to continually encounter one’s attacker.

Harvard President Drew Faust appointed a task force in April dedicated to reducing sexual assault and misconduct and better supporting those who experience it. “Harvard is deeply committed to fostering an educational environment free of gender-based discrimination, particularly sexual misconduct and sexual violence,” she said in a statement Wednesday.